Portable power-driven recessing apparatus



Dec. 30, 1952 Filed June 5, 1951 J. T. KENDALL PORTABLE POWER-DRIVEN RECESSING APPARATUS 2 Sl-IEETS-Sl-IEET l INVENTOR.

J. T KENDALL ATTORNEY Dec. 30, 1952 J. T. KENDALL 2,623,557

PORTABLE POWER-DRIVEN RECESSING APPARATUS Filed June 5, 1951 2 SHEETS-SHEET 2 FIG. 4

INVEN TOR.

J. T KENDALL ATTORNEY longitudinal finished edges.

Patented Dec. 30, 1952 OFFICE PORTABLE POWER-DRIVEN RECESSIN G APPARATUS John T. Kendall, Great Falls, Mont.

Application June 5, 1951, Serial No. 229,982

8 Claims. 1 This invention relates to building construction and more particularly to a method and apparatus for use in dry-wall construction to provide finished edges and invisible joints with conventional wallboard.

Manufacturers of wallboard usually provide relatively long strips of material which are slightly recessed on one surface along the two opposite However, this material has to be cut to different lengths and butt ends fitted together. It is almost impossible to finish the abutted ends smoothly without a raised joint which is unsightly, although the manufacturers furnish tape and joint filler for these purposes. Where the strip must be cut longitudinally to fit the wall of a room a similar problem arises along the longitudinal joints in providing a smooth finished joint.

An object of the present invention is to provide jacent edges of wallboard concealed and flush.

Another object of the invention is to provide a novel method of dry-wall construction wherein all pieces of the material, which at the present time are discarded, can be utilized, time will be saved and smooth invisible joints may be made along all of the contiguous edges.

Another object of the invention is the provision of novel apparatus for forming a recess along the butt ends and cut edges of wallboard to facilitate the formation of finished invisible joints along these edges.

A further object of the invention is the provision of apparatus for removing a thin layer of the filler material adjoining one of the two outer layers of flexible backing material found on conventional wallboard and pressing the backing sheet into the recess thus formed along one of the edges of the wallboard.

Another object of the invention is the provision of an attachment for a conventional portable power saw for forming a recessed edge on the conventional wallboard, and exhausting the dust thus formed to a suitable receptacle.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

' Fig. 1 is a perspective view illustrating one application of the present invention, specifically, an attachment for a portable power hand saw;

Fig. 2, an exploded View illustrating certain essential parts of the attachment shown in Fig. l on an enlarged scale;

Fig. 3, an end view of the apparatus of Fig. 1

with parts broken away to reveal certain details of construction and with the apparatus in position on the edge of a piece of wallboard:

Fig. 4, a section taken on the line 4-4 of Fig. 3;

Fig. 5, a fragmentary view of two pieces of wallboard with recessed edges in abutting relation; and i Fig. 6, a fragmentary view similar to that of Fig. 5 with the finishing strip in position to provide a smooth invisible joint.

Briefly stated, the invention comprises apparatus which may be an attachment for a portable power saw or a complete unit with an integral housing and base plate (not shown). A conventional rotary saw blade is driven by an electric motor to which a fan or impeller blade is adapted. to be coaxially attached-- A base plate is attached to the motor housing permitting the saw blade to extend therethrough a limited distance, and a pair of guide plates adjustably mounted thereon so that their adjacent faces may be disposed in spaced parallel relation. One of the guide plates is provided with a friction plate or shoe for pressing the backing sheet into the recess formed by the saw blade. Two sheets thus formed are placed with their recessed edges in abutting relation and the finishing strip is secured in the adjoining recesses to provide a smooth invisible joint, as shown in Fig. 6.

With continued reference to the drawings a conventional power saw I D is shown with a handle [2, switch l4 and electric conduit I6 for the op eration thereof. The motor [B is provided with a housing [8 to which the saw and blower housing 26 are secured by machine screws 22.

As shown more clearly in Fig. 3, a fan or impeller blade 24 is secured to the shaft 26 coa'xially with the saw blade 28 by means of a nut 30 on the threaded end of the shaft 32.

l The fan blade 24 will eject any dust formed by the cutting action of saw blade 28 out through the exhaust conduit 33. v

A base plate 34 is secured to the flanges at opposite ends of the motor housin I8 by machine screws 36 extending into threaded openings 38 in such base plate 34. This base plate also is provided with an elongated opening 4-0, through which the saw blade 28 extends, and two pairs of transverse slotted openings 42 and 44. Bolts 46 extend through the openings 48 in the flanged edge of a guide plate 563 and through the slotted openings 42 and are engaged by the wing nuts 52 for adjustably securing the guide plate 5i] in position. The guide plate 59 may also be provided 3 with reinforcing ribs 55 and a curved loading edge 55, if desired.

Another guide plate tit is also secured to the base plate 34 by means of bolts 58. These bolts extend through the openings to in the flanged edge of the guide plate 58 and through the slotted openings id and are engaged by the wing nuts 62 for adjustably mounting the guide plate 56. Such guide plate may have reinforcing ribs 63 and cammed edges fit.

A handle 65 may be provided having an end plate 68 with a pair of slotted openings 68 through which extend bolts l which engage the threaded openings l2 in the base plate 34 for securing the handle in position. The other end portion of the handle E i is provided with an opening it to receive a machine screw it engaging in the threaded opening as in the guide plate 56. The handle 85 not only serves for supporting and manipulating a device but also serves as a brace between the base plate at and the guide plat 55 to strengthen the device. Guide plate 56 is also provided with a friction plate or pressure shoe 82, the function of which will be described subsequently.

As shown in Fig. 3, the butt end or cut edge of a conventional piece of wallboard 84 having an intermediate layer at of plaster or other relatively rigid filling material and a pair of backing sheets 38 and as is placed, between guide plates 7 b and 5% and these plates are adjusted so that their adjacent surfaces will be parallel and in firm contact with opposite sides of the wallboard. The guide plate 5% being in the position described will cause the saw blade to out into the filler material ti; just inside of the backing sheet 38, as illustrated. The saw or cutter is moved along the edge of the wallboard in the direction indicated by the arrow in Figure 4 to cause the saw blade to remove a thin layer of the filling material 3% along and beneath the backing material Y88 and the shoe t2 presses or contracts the backing material as against the filling material remaining or into the recess thus formed.

In constructing a dry-wall from pieces of wallboard recessed in the manner described above, the contiguous recessed edges are placed in abutting relation, as shown in Fig. 5, and the space 52 between the edges of the backing sheets 88 is filled in with joint filler over which is applied a finishing tape 9 5 within the recessed portion. Thereafter the entire wall may be covered with paint, wallpaper or other desired finishing substance to provide a smooth surface, as indicated in Fig. 6.

It will be apparent that with the present invention it is possible to produce a smooth attractive wall surface on flimsy or unsubstantial wallboard which normally would be discarded.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and, therefore, the invention is not limited by that which is shown in the drawings and described in the s ecifioation, but only as indicated in the appended claims.

What is claimed is:

1. Apparatus for recessing the edges of wallboard comprisin a base plate, a pair of guide plates extending outwardly from one surface of said base plate and adjustably mounted thereon for positioning the opposed surfaces of said guide plates in spaced substantially parallel relation, one of said guide plates having a pressure shoe adjacent one end thereof in alignment with said saw blade, said shoe having beveled inner edges, the opposite end of at least one of said guide plates having a curved leading edge, a shaft mounted on the opposite side of said base plate and extending transversely with respect to the plane of said guide plates, drive means for said shaft, a rotary saw blade mounted on said shaft and extending through said base plate between said guide plates, an impeller blade mounted on said shaft adjacent said saw blade, a housing substantially enclosing said saw blade and impeller blade in conjunction with said base plate, an exhaust conduit extending from said housing, and a handle extending between said base plate and one of said guide plates for manipulating said apparatus and bracing said plates.

2. Apparatus for recessing the edges of wallboard comprising a base plate, a pair of guide plates extending from one surface of said base plate and with opposed substantially parallel surfaces, one of said guide plates having a pressure shoe adjacent one end thereof in alignment with said saw blade and having beveled inner edges, a shaft mounted on the opposite side of said base plate and extending transversely with respect to the plane of said guide plates, drive means for said shaft, a rotary saw blade mounted on said shaft and extending through said base plate between said guide plates, an impeller blade mounted on said shaft adjacent said saw blade, a housing substantially enclosing said saw blade and impeller blade in conjunction with said base plate, an exhaust conduit extending from said housing, and a handle extending between said base plate and one of said guide plates for manipulating said apparatus and bracing said plates.

3. Apparatus for recessing the edges of wall board comprising a base plate, a pair of guide plates extending outwardly from one surface of said base plate and with opposed substantially parallel surfaces, one of said guide plates having a pressure shoe adjacent the rear end thereof in alignment with said saw blade, said pressure shoe being substantially of the same thickness as the saw kerf and of substantially the same width as the depth of the saw kerf, a shaft mounted on the opposite side of said base plate and extending transversely with respect to the plane of said guide plates, drive means for said shaft, a rotary saw blade mounted on said shaft and extending through said base plate between said guide plates, and a handle extending between said base plate and one of said guide plates for manipulating said apparatus and bracing said plates.

4. An attachmest for a portable power hand saw having a rotary blade comprising a baseplate having means for attachment to the housing of said saw, an elongated slot through said base plate to permit a portion of said saw blade to extend therethrough, a pair of guide plates having flanged edges, means for adjustably securing said flanged edges to said base plate for positioning the opposed surfaces of said guide plates in spaced and substantially parallel relation,-said guide plates having outwardly curved leading edges along one end thereof, one of said guide plates having a pressure shoe adjacent the rear end thereof substantially in alignment with said saw blade, said shoe having beveled inner edges and being substantially of the same thickness of the saw kerf and of substantially the same width as the depth of the saw kerf, reinforcing ribs extending between said guide plates and said flanges, and a handle secured to one of said guide plates and adjustably secured to said base plate for manipulating said attach ment and bracing said plates.

5. An attachment for a portable power hand saw having a rotary blade comprising a base plate having means for attachment to the housing of said saw, an elongated slot through said base plate to permit a portion of said saw blade to extend therethrough, a pair of guide plates having flanged edges, means for adjustably securing said flanged edges to said base plate for positioning the opposed surfaces of said guide plates in spaced and substantially parallel relation, said guide plates having outwardly curved leading edges along one end thereof, one or" said guide plates having a pressure shoe adjacent the rear end thereof substantially in alignment with said saw blade, said shoe having beveled inner edges and being substantially of the same thickness as the saw kerf and of substantially the same Width as the depth of the saw kerf, and a handle secured to one of said guide plates and adjustably secured to said base plate for manipulating said attachment and bracing said plates.

6. An attachment for a portable power hand saw having a rotary blade comprising a base plate having means for attachment to the housing of said saw, an elongated slot through said base plate to permit a portion of said saw blade to extend therethrough, a pair of guide plates having flanged edges, and means for adjustably securing said guide plates to said base plat for positioning the opposed surfaces of said guide plates in spaced and substantially parallel relation, one of said guide plates having a pressure shoe adjacent the rear end thereof substantially in alignment with said saw blade, said pressure shoe being substantially of the same thickness as the saw kerf.

7. An attachment for a power saw having a rotary saw blade comprising a base plate, a pair of guided plates extending outwardly from one surface of said base plate and adjustably mounted thereon for positioning the opposed surfaces of said guide plates in spaced and substantially parallel relation, one of said guide plates having a pressure shoe adjacent the rear end thereof and adjoining said base plate, said shoe being adapted to be aligned with the rotary saw blade,

said pressure shoe being substantially of the same thickness as the saw kerf, and a handle extending between said base plate and one of said guide plates for manipulating said attachment and bracing said plates.

8. An attachment for a power saw having a rotary saw blade comprising a guide plate, means for mounting said guide plate in spaced and substantially parallel relation to said saw blade, a second guide plate having a, pressur shoe adjacent the rear end thereof, and means for mounting said second guide plate with one surface in spaced and substantially parallel relation to the opposed surface of said first guide plate and with said pressure shoe in alignment with said rotary saw blade, said pressure shoe being substantially of the same thickness as the saw kerf.

JOHN T. KENDALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 564,753 Jury et al July 218, 1896 1,136,181 Burgess Apr. 20, 1915 1,271,618 Reese July 9, 1918 1,806,528 Fegley et a1 May 19, 1931 1,883,392 Moll Oct. 18, 1932 1,932,511 Clarke Oct. 31, 1933 

